Abstract: The boiler taken up for analysis has a steam generating capacity of 250 tph, 11 MPa with 540°C of steam temperature. This study focuses on identifying the energy and exergy flow of each component of the system in order to identify the areas of major exergy loss. The plant components are grouped under three subsystems. The analysis was first made in the subsystems individually and as a whole. The coefficient of influence of important components was also studied. From the energy analysis, it has been found that the boiler system utilizes 88.41% of the total energy supplied to the plant and nearly 6.7% of heat supplied is carried away by the exhaust gas. The overall energy efficiency of the plant is found to be 31.15%. It has been noticed that the maximum exergy loss occurs in the furnace combustion chamber, i.e., 54.1% of the exergy supplied to Circulating Fluidized Bed (CFB). The exergy loss in the turbine is estimated to be around 8.3%. The maximum loss of exergy that occurs in boiler combustion chamber is due to irreversibility of the combustion process. The exergy efficiency of the boiler system is estimated to be 43.09% with respect to total exergy supplied to the plant. The overall exergy efficiency of the plant is evaluated to be 29.29%. Thus the study gives a frame work for the power plants, to conduct exergy efficiency studies in future.